By Michael Bristow
BBC News, Beijing
China has indefinitely postponed the release of an environmental report on the costs of economic development.
Pollution is a big problem for many parts of China
Several local governments are reported to have objected to the release of "sensitive" information about the pollution they cause.
Government officials from different departments also appear to disagree on how to calculate the figures.
But despite the setback, the man in charge of the scheme says the research should continue.
The project - to calculate how much money pollution costs China each year, the so-called "green gross domestic product" - was launched in 2004.
But the scheme seems never to have progressed smoothly.
Figures for 2004 - which revealed pollution cost China about 511bn yuan ($68bn, £33bn) or 3% of GDP - were not released until late last year.
Although officials have promised on a number of occasions to release the results for 2005, these figures have yet to materialise.
Now Wang Jinnan, the technical head of the project, has told the Beijing News that the release will be "postponed indefinitely".
"Some local governments are quite sensitive about the research and calculations for their provinces," he said.
"Separate trial provinces and municipalities have formally issued a request not to publish the calculation results, and have exerted pressure."
Mr Wang added that despite the difficulties, the research should continue.
There also appears to be a difference of opinion between the State Environmental Protection Administration and the National Bureau of Statistics.
Earlier this month, NBS head Xie Fuzhan seemed to cast doubt on whether a figure for the "green GDP" could even be calculated.
Wang's comments give a rare insight into the arguments going on within the government about how to achieve sustainable development.
They also show that even admitting how much damage pollution causes in China is a sensitive topic.
Last month, the Financial Times said the Chinese government had successfully removed controversial figures from a forthcoming World Bank report.
It said China had objected to statistics that revealed some 760,000 people died prematurely from air and water pollution each year.